The present invention relates to Heat Exchanged Crystal Growth (HECG) which uses a heat exchanger to control heat extraction and creates a controlled shaped temperature gradient for crystal growth. This process has far-reaching applications for growth of various materials with different shapes and sizes. An important aspect of this process is that both heat input and heat extraction can be controlled during crystal growth, and the heat extraction is near the solidifying crystal so that it is effective and allows for higher crystal perfection and faster growth rates. A specific application of HECG in which the heat exchanger is used in conjunction with the Czochralski (Cz) process to produce square (100) silicon ingots for photovoltiac applications is referred to as Heat Exchanged Czochralski (HEC) process. The process is described for growth of single crystal silicon, however, it has applicability for other materials in single crystal or multicrystalline forms.
Crystalline silicon produced using ingot technologies is used in large area photovoltiac modules. By reducing the cost and increasing the efficiency of wafers produced from silicon ingots, photovoltiac modules can be produced with high efficiency.
Other applications also require crystals of various shapes and sizes, which are not conveniently produced using current methods.
It is therefore an object of the present invention to provide a method for growing crystals of various materials with different shapes and sizes.
An additional object of the present invention is to provide a method for growing crystals while controlling both heat input and heat extraction.
It is a further objective of the present invention to provide a method for growing crystal with improved crystal perfection.
It is a further object of the present invention to provide a method for growing crystals with improved control and at high-growth rates.
It is also an object of the present invention to provide a method for producing high-quality shaped single crystal (100) silicon at low cost and high-efficiency.